Grants access to the test modelclients to the development team

For trumpet testing.
This should replace James Jarrett's static account.

test/aws-us-gov/mdr-test-modelclient/005-iam/terragrunt.hcl

@@ -34,4 +34,5 @@ inputs = {
   tags = {
     Terraform = "aws/${basename(get_parent_terragrunt_dir())}/${path_relative_to_include()}/"
   }
+  iam_additional_trusted_arns = [ "arn:aws-us-gov:iam::701290387780:role/user/mdr_developer_readonly" ]
 }

test/aws/mdr-test-modelclient/005-iam/terragrunt.hcl

@@ -34,4 +34,5 @@ inputs = {
   tags = {
     Terraform = "aws/${basename(get_parent_terragrunt_dir())}/${path_relative_to_include()}/"
   }
+  iam_additional_trusted_arns = [ "arn:aws:iam::471284459109:role/user/mdr_developer_readonly" ]
 }